8842A
Instruction Manual
6
5-15.
5-16.
OHMS PROTECTION......................................................................... 5-13
5-17.
OHMS FUNCTIONS ........................................................................... 5-13
5-18.
2-Wire Ohms.................................................................................... 5-13
5-19.
4-Wire Ohms.................................................................................... 5-15
5-20.
A/D CONVERTER .............................................................................. 5-15
5-21.
Timing/Data Control ........................................................................ 5-17
5-22.
Precision DAC ................................................................................. 5-18
5-23.
A/D Amplifier .................................................................................. 5-18
5-24.
Bootstrap Supplies ........................................................................... 5-18
5-25.
DISPLAY ............................................................................................. 5-19
5-26.
KEYBOARD........................................................................................ 5-19
5-27.
DIGITAL CONTROLLER................................................................... 5-19
5-28.
5-29.
5-30.
5-31.
5-32.
5-33.
5-34.
5-35.
GUARD CROSSING ........................................................................... 5-24
5-36.
POWER SUPPLY ................................................................................ 5-25
5-37.
5-38.
5-39.
Guard Crossing................................................................................. 5-26
5-40.
5-41.
Signal Conditioning ......................................................................... 5-27
5-42.
5-43.
5-44.
VAC Scaling .................................................................................... 5-27
5-45.
mA AC Scaling ................................................................................ 5-28
5-46.
5-47.
Maintenance ....................................................................................... 6-1
6-1.
INTRODUCTION................................................................................ 6-3
6-2.
PERFORMANCE TEST ...................................................................... 6-4
6-3.
Diagnostic Self-Tests ....................................................................... 6-4
6-4.
DC Voltage Test............................................................................... 6-5
6-5.
6-6.
Resistance Test................................................................................. 6-8
6-7.
DC Current Test ............................................................................... 6-9
6-8.
6-9.
CALIBRATION ................................................................................... 6-10
6-10.
6-11.
INITIAL PROCEDURE .............................................................. 6-11
6-12.
A/D CALIBRATION .................................................................. 6-12
6-13.
6-14.
6-15.
6-16.
6-17.
6-18.
6-19.
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